1. Field of the Invention
The present invention relates to an infrared sensor, and particularly, to an infrared sensor assembly for precisely detecting a location where a heat source is generated and a refrigerator having the infrared sensor.
2. Description of the Background Art
Generally, an infrared sensor detects physical quantity and chemical quantity such as a temperature, a pressure, and an intensity of radiation by using infrared rays having a wavelength which is longer than red light of visible rays and shorter than microwave among electromagentic waves, and converts the detected physical quantity and the chemical quantity into electricity quantity in which a signal process is possible, thereby outputting.
Especially, a thermopile infrared sensor is used as a non-contact far distance temperature measurement device which can measure a temperature of an object without directly contacting heat to the object.
FIG. 1 is a sectional view of the thermopile infrared sensor assembly in accordance with the conventional art.
The infrared sensor assembly according to the conventional art comprises: a supporting frame 102; an infrared sensor 104 fixed to the supporting frame 102 for detecting infrared rays radiated from an object; and a case 108 fixed to the supporting frame 102 and having an infrared filter 106 mounted at an upper surface thereof, the case for receiving the infrared sensor 104.
The infrared sensor 104 includes: a receiving portion 110 arranged at an upper surface thereof for detecting infrared rays radiated from the object; a fixation portion 112 for fixing the receiving portion to the supporting frame 102; and a terminal 116 connected with the receiving portion 110 by a lead line 114 for transmitting a signal value received from the receiving portion 110 to a control unit (not shown).
In the conventional infrared sensor assembly, if a heat source is generated at a predetermined point, the receiving portion 110 detects infrared rays radiated from the heat source and applies to the control unit. Then, the control unit determines a point where the heat source is generated and a temperature of the heat source. At this time, the infrared filter 106 transmits only the infrared rays, thereby measuring more precisely.
However, in the conventional infrared sensor assembly, since a receiving angle (xcex8) taken to the receiving portion is wide as approximately 60xc2x0, it is easy to detect whether the heat source is generated or not, but it is difficult to measure a precise point where the heat source is generated.
Therefore, an object of the present invention is to provide an infrared sensor assembly which can precisely measure a location of the heat source by narrowing a receiving range of the infrared sensor.
Also, another object of the present invention is to provide a refrigerator to which the infrared sensor is applied, in which a location where a high temperature load inside the refrigerator is generated is precisely detected by narrowing a receiving angle of the infrared sensor mounted in the refrigerator.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided an infrared sensor assembly comprising: an infrared sensor fixed to a supporting frame for receiving infrared rays generated at a heat source; a case having the infrared sensor mounted therein and an infrared filter mounted at an upper surface thereof, the infrared filter transmits only the infrared rays; and a receiving range limiting means prolonged from an outer circumference surface of the case with a predetermined height for limiting a range of the infrared rays received into the infrared sensor so as to precisely detect a location of the heat source.
The receiving range limiting means includes: a housing mounted outside of the case and formed above an upper surface of the case with a predetermined height; and an infrared lens mounted at an upper surface of the housing for limiting a receiving range of the infrared rays generated at the heat source.
The housing of the receiving range limiting means formed as a cylindrical shape having a predetermined length includes a mounting groove to which an outer circumference surface of the supporting frame is fixed at a bottom inner circumference surface thereof; and the infrared lens mounted at an upper surface thereof.
A diameter of the infrared lens 24 of the receiving range limiting means is differently set according to a receiving range of the infrared rays generated from the heat source.
The infrared lens 24 of the receiving range limiting means is made of chalcogenide based glass.
The infrared lens 24 of the receiving range limiting means is formed to limit a receiving angle from the heat source as about 5xc2x0.
The infrared lens 24 of the receiving range limiting means is provided with a height control means for controlling a height of the housing divided into an upper housing and a lower housing.
The height control means includes a female thread formed at an inner circumference surface of the upper housing and a male thread formed at an outer circumference surface of the lower housing. At this time, the female thread and the male thread are engaged to rotate the upper housing, thereby controlling a height of the housing.
A refrigerator having the infrared sensor according to the present invention comprises: a body divided into a freezing chamber and a chilling chamber by a partition wall and having a predetermined space to store food; a fan attached to an upper portion of the freezing chamber for forcibly circulating cool air cooled by passing the freezing cycle; a cool air discharge duct for discharging cool air blown by the fan into the chilling chamber; infrared sensors mounted at an inner wall of the chilling chamber for detecting a temperature and a generation location of a high temperature load by receiving infrared rays generated at the high temperature load; and a receiving range limiting means mounted at an upper portion of the infrared sensor with a predetermined interval for limiting a receiving range of the infrared rays received into the infrared sensor so as to precisely detect a location where the high temperature load is generated.
The receiving range limiting means is mounted at an outer portion of the infrared sensor mounted at an inner wall of the chilling chamber, and includes a housing formed above the infrared sensor with a predetermined height; and an infrared lens mounted at an upper surface of the housing for limiting a receiving range of the infrared rays generated at the high temperature load.
The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.